In short
- 888 ADU permits on record, nearly all since 2020.
- 237 in 2025, up 20% from 2024.
- Typical permit time: 428 days from application to permit (median of 259 permits with both dates recorded, including planning review).
About this data
- Source: California HCD Housing Element Annual Progress Reports. The state data does not say whether an ADU is detached, attached, a garage conversion or a JADU, so most records show as 'unknown'. Permit valuations are not published in this source. Timelines use the application date the city reported to the state, matched to the permit where possible; some cities report their planning application date, so timelines can include planning review. Each project is counted once, in its building-permit year (or completion year when no permit date was reported).
- Oxnard reports its planning case numbers and planning application dates to the state, so its timelines run from the planning application to the building permit and are longer than building review alone.
Permits by year
Permits by year and type (table)
| Year | All ADU permits | Garage conversions | Detached |
|---|---|---|---|
| 2018 | 3 | — | — |
| 2019 | 14 | — | — |
| 2020 | 31 | — | — |
| 2021 | 95 | — | — |
| 2022 | 119 | — | — |
| 2023 | 192 | — | — |
| 2024 | 197 | — | — |
| 2025 | 237 | — | — |
“—” means the source for that year does not report ADU type.
Read more: ADU types explained
Not counted above: 473 approved projects with no building permit reported yet.
ADU rules in Oxnard
State law check: The city adopted a new ADU ordinance in January 2026, after HCD letters (May and October 2025) called the old one noncompliant; we haven't seen an HCD review of the new one.
| Rule | Oxnard's code | State law guarantees |
|---|---|---|
| Maximum size | Attached: 1,200 sq ft or 50% of the house (at least 800). Detached: 850 sq ft (1 bedroom or less) or 1,200 sq ft. State-law detached ADU 800 sq ft. Junior ADU 500 sq ft. | At least 850 sq ft (1,000 sq ft with 2+ bedrooms) must be allowed; an 800 sq ft detached ADU always is. Conversions of existing space have no size cap. Junior ADU: up to 500 sq ft. |
| Height | Locally regulated ADUs: 2 stories and 25 ft. State-law ADUs: 16 ft (18 ft near transit, plus 2 ft). | Detached: at least 16 ft (18 ft within ½ mile of transit, plus 2 ft for a matching roof). Attached: 25 ft or the zone's limit, whichever is lower. |
| Setbacks | 4 ft side and rear; the zone's front setback. | No more than 4 ft side and rear; none for conversions of existing space. |
| Parking | 1 space for an attached or detached ADU unless exempt; none for state-law ADUs or junior ADUs. | At most 1 space; none within ½ mile of transit and in several other cases. No replacement parking when a garage is converted. |
| Owner living on site | None for ADUs. Junior ADU: only when it shares a bathroom with the house. | None for ADUs. A junior ADU that shares a bathroom with the house requires the owner to live in one of them. |
| How many on a single-family lot | One attached ADU, one junior ADU and one detached ADU. | One ADU converted from existing space, one junior ADU and one new detached ADU (up to 800 sq ft). From January 1, 2027: two new detached ADUs (a city then needn't allow a junior ADU on that lot). |
| Short-term rentals | More than 30 days. | No guarantee: cities may require rentals of more than 30 days, and junior ADUs can't be short-term rentals. |
- Objective roof and siding standards, and design standards for historic properties.
- Pre-approved ADU plans are accepted.
Where local rules conflict with state law, state law controls. Sources: Oxnard Ordinance 3072 (Jan 6, 2026) · HCD letter (May 12, 2025) · HCD letter (Oct 8, 2025); HCD's list of review letters; California ADU rules. Verified Sep 29, 2026. Rules change and every lot is different: confirm with the city before you design.
How long permits take
| Type | Median days, application to permit | Middle half | Permits |
|---|---|---|---|
| Unclassified | 428 | 315 – 570 | 259 |
Middle half: the range covering the middle 50% of permits (a quarter were lower, a quarter higher).
Read more: ADU permit times across Ventura County · How long ADUs take to build
From permit to completion
Of the 407 ADU permits Oxnard reported issuing from 2020 through 2023, 230 (57%) have a completion reported to the state. For those, the median time from permit to completion was 10 months.
The state reports don't record expired or cancelled permits, and a completion the city hasn't reported looks the same as an unfinished project, so the share is a floor. Years with incomplete reports are left out.
What neighbors declared as cost
Cost data (declared permit valuations) is not published for this area in these sources.
Read more: How to choose an ADU builder
An ADU builder serving Oxnard? Feature your business on this page.
Questions about ADUs in Oxnard
How many ADUs have been permitted in Oxnard?
Public records show 888 ADU permits in Oxnard through 2025, nearly all since 2020. 237 in 2025, up 20% from 2024. These counts come from the city's reports to the state, which place a project in its completion year when no permit date was reported.
How long does an ADU permit take in Oxnard?
Among the 259 ADU permits in Oxnard with both dates recorded, half were issued within 428 days of the application; the middle half took 315 to 570 days. That includes plan-check corrections and resubmittals, not just the review itself. Oxnard reports its planning application date, so these times include planning review.
Can I build an ADU on my property in Oxnard?
California law allows ADUs on most lots with a house, including in Oxnard, but what you can build depends on your lot, local rules and utilities. This site shows permits, not eligibility. See California ADU rules.
Where do I apply for an ADU permit in Oxnard?
Apply with the City of Oxnard: a Planning pre-review by email, then a submittal to Building and Engineering. Official ADU page.
How current is this?
- State annual progress reports: through 2025 (published once a year)
How our data works · Download the data · Free to reuse with credit to SoCal ADU Tracker (socaladutracker.com), under CC BY 4.0.